I recently did plugs and a few coil packs at 120,000 miles. It ran great for about 150 miles. It started to bog over the coarse of 20 or so miles of driving. I did replace fuel pmup, filter, screen (sock). Fuel pressure is @ 30ish upon idle. When I drive it it will goes to 40psi and stops there and is steady ( I believe it should go to 50-55psi). As I gas it @ idle it rev's great. The van will not go over 30mph+-. The check engine light is off. I have no way to check for soft codes because I can't drive it. It has the symptons as if it were running out of gas. Any suggestions @ all? This is my work van so I need this baby up and running!! Is there another place I may post this? Thanks in advance.

 

welcome to FTE.what type of plugs did you use? did you check the gap on the plugs?one more quick thing to check the pvc hose where it attaches on the back of the intake ,the rubber elbows are bad for rupturing.

 

Thanks Cris, I did just remove and check the elbows and there was no visible cracks. I believe I had used Autolite platnum plugs. I was told the plugs are pregapped and it's not a good idea to gap them due to the platnum coating may get chipped. Keep in mind it ran fantastic for a while until it produced these symptoms. Also one thing that may help in diagnosing is that it had ran out of fuel shortly before these symptoms.

 

Replace the fuel filter and go from there. I always check the gap on the plugs but very VERY rarely need to fix them.

 

Almost sounds like a clogged cat converter.

 

Thanks Jimmy, I was thinking along those lines myself. Is there a way to test them without cutting into anything? I believe this van (E250) has 2. I won't be able to check until the morning.

 

Can you disconnect an O2 sensor and check for preformance changes?

 

Sounds like plugged filter or your new pump went out when you ran out of fuel. Fuel pressure is a little low.

 

Most muffler shops will check them for free. They drill a small hole before the cats and use a pressure gauge to check how much backpressure that you have.

 

Thanks Guy's. I ran the truck out of gas before I changed the pump. It's not drivable (20 mph) right now so any testing that needs to be done I have to do it myself. Has anyone done this test before?

 

I will have to say, start with a new fuel filter. To me, it is a classic sign for an engine to run fine without load and to stumble or bogg under load with a clogged fuel filter. The Cat converter testers that I have used screwed into the o2 sensor hole and used a normal cylinder compression tester to measure backpressure. you will have to test it both pre and post cat on both sides to get an accurate measurement. I would start with the simple stuff first and change the fuel filter, I'm not sure of the "normal" fuel pressure, but 40psi sounds a bit low to my tired brain. I would think that 55-60 would br more like it. Good luck...

 

Unless you are running an aftermarket fuel pump (or two) you'll never see even close to 50 psi of fuel pressure. 30 - 40 psi is the normal range.

 

As I said in my post I had replaced the fuel filter when this started. I asked a couple other people and they say that 40psi of fuel may be about right, however Mitchel suggest up to 50psi. I will see what I can do about testing air pressure before and after the cats. Thanks Guys!

 

UPDATE, I had it scanned. We came up w/the CHT amongst other things. I replaced it (without removing the intake manifold) and there is no difference. I am waiting for another scan. It is running in limp mode. Coolant is good. I'll just keep scanning. BTW this was not throwing the check engine light. I'll get it if it's the last thing I do!!!!!

 

I'll second this recommendation. It happened to me on my previous truck. Anything over 1500-2000 RPM, the engine would bog down. A shift to a lower gear would just make it run slower!

Easy to test, just disconnect your exhaust system upstream from the cat and take the truck for a loud test drive. You'll know right away if this is the problem.